It's unspoken road etiquette: flash your lights to warn oncoming traffic of speed enforcement zones.
"Well, I just did it," said Raoul Robar of Minneapolis, Minnesota.
"Oh yes, I think it's good for everybody to do it; gives somebody a warning, heads up," said Robert Walkiewicz of Plymouth.
"As long as it slows the traffic down, and if that's the main goal, I don't see anything wrong with it," added Kurt Stromquist.
But as popular as it is in Michigan, in Florida, motorists have been ticketed for their warning flashes, and our Facebook fans have asked us to shed some light on the issue. What we found, Florida courts tossed away those tickets, and lawyers are trying to prove that flashing lights as a warning is constitutionally free speech. Michigan State Police seem to agree.
"I don't have any problem with that whatsoever," said Sgt. Kevin Dowling. "There's no law that says you can't turn your lights on and off.
Police also say motorists flash their lights for a number of reasons, from deer crossings to inclement weather, and to try and ticket them for one would be impossible.
"Certainly we can't read people's minds as to why they might be flashing their lights," Dowling said.
While flashing your lights might be legal and many people may do it, some officers say that it might not be the brightest idea.
"The only thing I'm going to say is if you're required to have your lights on because of darkness, you probably shouldn't turn them on and off; that would technically be a violation," Dowling said. "If you're doing it to a point where you may distract another driver, I think that could be a potential problem."
Troopers say the best way to utilize the unspoken warning signal is briefly and in the daylight.